The man who died after collapsing on Errigal mountain in County Donegal at the weekend was Carl Henderson, from Moira, County Armagh.
Donegal mountain rescue team said the hill walker, a father-of-three in his 40s, went into cardiac arrest while climbing the peak.
Paramedics, who were hiking on the mountain, tried to resuscitate him.
He was then airlifted by a Coast Guard helicopter to Letterkenny University Hospital, where he was pronounced dead.
Emergency services made their way to the scene after being called on Saturday afternoon.
The mountain rescue team said its volunteers were tasked to the area at 12:48 local time by the National Ambulance Service (NAS).
“Our team immediately initiated full call-out protocols with rendezvous at Errigal car park,” a spokesperson said.
“On arrival, NAS already had an advanced team on the mountain with an additional medical team just arriving on scene.
“CPR was initiated by NAS staff who were hiking on the mountain.”
Gardaí (Irish police) said the man’s death was being treated as a medical incident and the coroner had been informed.
Preparations were underway on Monday to carry out a post mortem examination to determine the cause of death.